Please note! This essay has been submitted by a student.
Urban green spaces are the urban lungs of urban residents with urban vegetation widely reported to improve air quality(Schöpfer, Lang, & Blaschke, n.d.) (F.J. Escobedo. & D.J. Nowak, 2009, F.J. Escobedo, T. Kroeger, & J.E. Wagner, 2011), green space is an area in urban covered mainly by vegetation and constitute parks, gardens and recreation venues (Gupta, Kumar, Pathan, & Sharma, 2012). Green spaces in cities are also of great significance in water regulation(Elmqvist et al., 2015), trees intercept rainfall, other vegetation, and permeable soils in urban areas play an important role in reducing the pressure on the drainage system and in lowering the risk of surface water flooding (Pataki et al. 2011). Reduction of urban heat island effect is directly linked to increased greening of urban areas (Bowler, Buyung-Ali, Knight, & Pullin, 2010; Pataki et al., 2011), a 10% increase in tree canopy cover may result in a 2–3oC decrease in ambient temperature (Gill, Handley, Ennos, & Pauleit, 2007) and save large amounts of energy used in air conditioning (Nicholson, 2003).
Increase in population and development activities increases demand for manufacturing, trade and transport, and travel services, has resulted in increased pressure on open spaces with most lands usurped by buildings and roads, little interstices are left for greenery, resulting in grave deficiency in public open spaces mostly in developing cities like kampala. Urban developments are done sometimes in haste with little regard to environmental quality (Olembo and de Rham 1987; Herz et al. 2003) as a result the need to dilute the built-up harshness with green areas usually neglected (Marcotullio 2001).
Decrease in green spaces in urban areas results in increase in urban heat island effect, the increased heat in urban areas requires an increase in the amount of energy used for cooling buildings, leading to a deterioration of air quality and negative health effects (Gill et al., 2007; Whitford, Ennos, & Handley, 2001).
Kampala city authority physical planning department should implement spatial development concepts, which promote both economic and social potential for urbanisation and inspire protection of green spaces for future generations.
However, little has been done by the authority to protect green spaces within the city which are decreasing at a high rate where most of the green spaces have been replaced by impervious surfaces. Infiltration of rainfall has reduced, runoff has increased to about six times than that which would occur in natural terrain and floods are now more frequent and more severe with the occurrences becoming erratic and unpredictable, the mean annual temperature is expected to increase by 1.0 to 3.1°C by the 2060s, and 1.4 to 4.9°C by the 2090s (IPCC, 2012) urban heat island effect likely to increase which can result in numerous negative side effects for residence of the community. As higher temperatures result in greater energy consumption and air conditioning costs, and in the most extreme conditions can even result in health complications (U.S. Environmental Protection Agency (EPA), 2014).
Conserving green spaces through implement street green space in the form of storm water retaining planter boxes, increasing on rain gardens between roadways and planting trees along the streets, this encourages natural filtration of the rainwater into the soil rather than redirecting the water along the street into the municipal sewage system contributing towards storm water management.
To establish strategies for conservation of green spaces in urban areas to mitigate adverse effects of climate change.
The study will be undertaken in Kampala central division which is one of the five divisions in Kampala capital city. The division comprises the central business district of the largest city in Uganda and includes the areas of Old Kampala, Nakasero and Kololo. These areas are the most upscale business and residential neighborhoods in the city. The division also incorporates low income neighborhoods including Kamwookya, Kisenyi and Kampala’s Industrial Area. The coordinates of the division are: 0°19’00.0″N, 32°35’00.0″E (Latitude: 0.316667; Longitude: 32.583333). The division comprises about 20 parishes. Kampala central division has tropical climate with two rainy seasons from March to May and from September to December. The mean annual rainfall is 1241.2 mm with the hottest month being February 23oC avg and the coldest month being August 22oC avg. This study focuses on the change in land-covers and land surface temperature (LST) of three downtown low income neighborhoods Kamwookya, Kisenyi and Kampala’s Industrial Area where the population density is higher and green cover expected to be more threatened and three urban area Kololo, Nakasero and Old Kampala where preservation of green spaces has been observed.
Current LANDSAT and ALOS satellite images captured at daylight with transparency and low cloud’s coverage for Nakawa division to be obtained, processed using ERDAS/ENVI 5.1 and analysed in ArcGIS 10.4 to obtain the land cover maps in the division in 2018
Using LANDSAT images from 2008, 2013 and 2018 and ALOS images from 2008 and 2018, change detection will be carried out using change analysis after supervised classification of each image to determine changes in green space coverage and impermeable surface. The overall accuracy and kappa value (Kap) will be selected as the evaluation criteria for image classification. An error matrix will be generated based on the test samples for each land cover map.
The urban green space index per capita will be obtained to assess the quality of green coverage, then the index will be used to evaluate the status of urban green space
Model development prediction: using Markov chain’s analysis (Van et al., 2017) ,where two variables, the area of real coverage of the four layers in 2018 and probability transition matrix among real coverage layers from 2008 to 2018 will be used. The total area of these 4 layers in 2018 will be calculated directly after conducting the satellite images process. Probability transition matrix among real coverage layers will be identified on ArcGIS software after practicing the process of collapsing two real coverage classification’s maps in 2008 and 2018 following Van et al 2017.
Landsat data, local historical temperature data recorded by the Weather Underground website (http://www.wunderground.com) and Hydro- meteorological station will be used to calibrate the estimated models for urban Land surface temperature (LST) from TIRS, TM and ETM Landsat images (Yuan, Sawaya, Loeffelholz, & Bauer, 2005)
Following (Whitford et al., 2001) a hydrological model adopted from Pandit and Gopalakrishnan (1996) will be used to estimate runoff coefficients for rainstorms.